[tophat9000]

Im not sure how you would not need their device if there fiber?
home routers will have an Ethernet interface for the WAN (there are some that have ADSL or Cable interface but rare)

so Verizon would have to have something that takes fiber on one side and gives you an Ethernet drop on the other side.

The point of ip is to give a common global networking addressing scheme (layer 3) to dissimilar data link physical layer devices (layer 2/1)

in other words your home router doesn't know how to talk to a fiber data link ...Verizon provide you a box that has a fiber interface on one slide in an Ethernet interface on the other and each of those interfaces gets an IP address ...or maybe just the ethernet interface.. but the verzion box still does the translation between fiber and Ethernet protocol at the datalink Layer 2

[driftdiver]

There’s modem on the outside that coverts fiber to ethernet. This then terminates on a small wifi router inside. So instead of taking their cheap little router that has the backdoor built in you use your own.

They don’t have any access past the new device.